Not applicable.
Not appendix.
This invention is regarding to automotive accessory or low voltage industrial motor control relays; door lock relay, power window control relay, power seat control relay, antenna control relay, cassette motor control relay, disk control motors, and more. However, for the illustrative and clarity purpose, a general purpose relay control system is explained as an example with up and down input signal notation. In some other applications, these could be right and left operations. Therefore, this invention is not limited only to a specific function, but extended to all relay applications described previously.
In a prior art (conventional) dual function motor control system, 2 separate relays, one for up and the other one for down functions, are assembled together in a package as a dual functional relay device. One relay is activated by the UP input signal from a UP switch and the other relay is activated by the DOWN input signal from a DOWN switch.
The conventional electromechanical relay has several mechanical metal contacts, which are prone to be corroded because of heavy current passing through the contacts when the relay is energized.
FIG. 2 shows the structure of a prior art (conventional) reversible motor control relay circuit. If either up or down switch is pressed, heavy current is flowing through the respective coil, energizing the relay. The coil electron current is flowing from the relay Ground (1), through the coil, point (5), up switch contact, 20A fuse, to V+. The up function motor current path starts from the Ground (1), Ground side contact of the down relay, point (3), reversible control motor (150), point (4), activated side of the up relay, 30A fuse, to V+.
The manufacturing process for a mechanical device is, in general, more difficult than that of an electronic device. For a prior art (conventional) motor control relay, it requires quite heavy coil current to activate the relay.
To improve such an inherent deficiencies of the electromechanical relay, the solid state relay has been developed for many different applications. However, the most of them are functionally limited to single pole single throw switch mode. In general, those used in computer related system are low power and low voltage relays and those used in industrial application are mostly high voltage high power solid state relays. Most automotive relays should be capable of controlling devices with low voltage and high current load. Therefore, the products of this invention can be mostly utilized for the automotive and also for computer applications.
in a industrial application of a relay device, it is a general trend to replace a electromechanical relay to a solid state relay because the latter has the features of the better durability, less power consumption and easier manufacturing process. As explained in the background section, the operation of a general purpose relay control system is described for the illustrative purpose only and its application is extended to all applicable accessory control devices. With the advantageous solid state internal structure, a dual function solid state relay of the present invention has the same functionality and external connection features as those of the conventional electromechanical relays for the respective operations. The product of the present invention can easily replace electromechanical dual function relays without any modification for the interconnections with the existing related devices or circuits.
The new invention provides 6 terminals, 2 for the up and down input signals, 1 for V+ connection, and 1 for Ground connection, and 2 for the output connections to the reversible motor. The internal structure of the new invention includes 4 semiconductor switches, 2 for the up function and remaining 2 for the down function. Each function requires 2 semiconductor switches, 1 for power supply connection, 1 for Ground connection to the control motor of the respective function. Each semiconductor switch is made of solid state devices, either transistors MOSFETs, SCRS, or combination of the several those devices. The arrangement of the solid state devices of a semiconductor switch is either Darlington structure, SCR structure, driver and power transistor combination, or single power device arrangement. With the addition of the input signal control circuit to the dual function solid state relay device, it produces the composite device of the reversible solid state control device. Two types of special semiconductor switches can be utilized for a solid state relay where low power supply is available and high power is required. One type is to connect V+ to a load and the other one is to connect Ground terminal to the load. When activated, those switches drop much less voltage across the switch devices than SCR or Darlington devices. Accordingly, they consume much less powers and generate less heat.